The primary goal of this project is to develop a macaque monkey model for complex-partial seizures during the first year of life. The research is important because an estimated 3 5% of children in the United States have at least one seizure before the age of three. There is concern that early seizures may adversely affect cognitive and emotional functioning during childhood. Cranial assemblies are implanted on project animals using stereotaxic surgical techniques. Bicuculline is then microinfused into an area deep within the piriform cortex to induce complex-partial seizures. Each monkey has three seizures within the first months of life and then is assessed for one year on a battery of behavioral, cognitive, and neurological measures. During the past year, we obtained data on nine animals. Our results indicate that seizures can be induced reliably in very young subjects. In addition, prolonged seizures at 3 6 months of age may result in hyperexcitability and subtle cognitive deficits, and may produce brain damage and abnormal EEG activity.